In postal and credit operations, as well as other mass document handling devices, certain documents and envelopes are coded using a bar code and/or optical character keying and printing module, and thereafter the documents are sorted by using a bar code or optical character reader and a sorter. Certain sorting systems in current use also employ image lift address verification units, which electronically recreate the address information normally found on one side of a document, piece of mail, or package. Since typical bar code readers, optical character readers and image lift cameras can economically read only one face of a document at a time, it is important that the documents being transported by the system all face in a uniform direction as they pass in front of the bar code or optical character reader, or an image lift camera.
One prior system for achieving document separation when the documents are not uniformly oriented is disclosed in Freeman et al. U.S. Pat. No. 4,119,194. This patent discloses a single station system for sorting postage bearing mail based upon the location of the postage indicia, utilizing a chute-like receptacle which then ejects and directs pieces to separate right and left conveyors, depending upon whether postage indicia is present adjacent to the right or left edge of an envelope. The conveyors circle and form a closed loop connected to a document transport apparatus. This patent, however, does not disclose a document transport apparatus or system for rapidly transporting a high volume of documents such as mail into a sorting apparatus, while at the same time re-orienting the facing of certain documents and advancing such re-oriented documents back into the moving document transport system.
Another device for re-orienting documents is shown in Svyatsky U.S. Pat. No. 5,048,814, which is commonly owned by the parent entity of the assignee of the present invention. This patent discloses a single document orientation mechanism for reversing the facing of individual documents delivered from a stack of multiple documents while maintaining a predetermined directional document stream. An embodiment of the present invention utilizes and coordinates a plurality of the document orientation mechanisms shown in this patent in seriatim to re-orient and maintain the continual flow of documents along a document transport system.
Mail and document handling systems today must be capable of transporting and sorting documents such as catalogs, packages and other materials of varying thickness. Therefore, devices and mechanisms utilized in mail transport systems must be capable of reviewing and advancing such documents without unduly bending the document during transport. Also, consideration must be given that certain thicker documents resist bending as the documents are advanced through a document transport systems. Therefore, mail handling systems must employ document handling devices or elements which are adapted to handle thicker documents which should not be subject to bending stresses, and documents which inherently resist bending as they are advanced through the mail transport system.
Certain elements of mail and document transport systems are required to pivot or otherwise move rapidly during the operation of the system to handle large volumes of mail in a short time period. This movement is resisted by the inherent inertia of the element or elements to be pivoted or moved, and the inertia is directly proportional to the size of the moving element. It has been discovered that the productivity and efficiency of document handling systems can be increased by incorporating movable elements of reduced size such that minimal inertia is encountered upon operation of the pivotal or moveable element.
In present document conveying and handling systems, errors in document orientation occur at the introduction of the individual document into the processing system. It is important that devices for correcting such errors, such as a document re-orienting apparatus, be property placed along the document path to correct the error prior to additional processing steps and interaction of each document with additional downstream equipment or detectors. It is also important that error sensing devices be disposed sufficiently ahead of the re-orienting device to allow proper control of document infeed and of correction of such error while maintaining maximum productivity of the system.